Spike investigate what is needed to automate the flow to obtain the pull-secret

[gbraad]

User provides the Red Hat credentials, and the pull-secret (PII) gets obtained. This prevents the case where we leave a file on the machine (safely stored in the credential store).

• Related to: Offer different ways to "Provide a pull secret" #16
• Depends on: Basic validation and/or show more details about the provided pull-secret  #17